Front

What is a unit rate?

Back

A unit rate is a comparison of two different quantities when they are combined together. It is expressed as a quantity per one unit of another quantity.

Front

How do you calculate the unit rate from a total cost and quantity?

Back

To find the unit rate, divide the total cost by the total quantity. For example, if a box of cereal costs $3.59 for 30 oz, the unit rate is $3.59 ÷ 30 oz = $0.1197, which rounds to 12 cents per ounce.

Front

What does it mean for a relationship to be proportional?

Back

A relationship is proportional if two quantities maintain a constant ratio. This means that as one quantity increases or decreases, the other does so in a consistent manner.

Front

How can you determine if a graph represents a proportional relationship?

Back

A graph represents a proportional relationship if it is a straight line that passes through the origin (0,0).

Front

What is the constant of proportionality?

Back

The constant of proportionality is the ratio between two proportional quantities. It is the factor by which one quantity is multiplied to obtain the other.

Front

How do you set up a proportion to solve for an unknown?

Back

To set up a proportion, create a fraction that compares two ratios. For example, if you know the cost for 6 people is $39, you can set up the proportion: 39/6 = x/9, where x is the cost for 9 people.

Front

What is the formula for finding the cost per item?

Back

The formula for finding the cost per item is: Cost per item = Total cost ÷ Number of items.

Front

How do you find the best deal when comparing prices?

Back

To find the best deal, calculate the price per item for each option and compare them. The option with the lowest price per item is the best deal.

Front

What is a ratio?

Back

A ratio is a comparison of two quantities that shows the relative size of one quantity to another.

Front

How do you calculate the total cost for a different number of items based on a known cost?

Back

To calculate the total cost for a different number of items, use the unit rate or constant of proportionality. Multiply the unit cost by the new quantity.